R3=3 Ом I1=2 А I3=3 A U1= 450 B r=6 Ом

Question

R3=3 Ом
I1=2 А
I3=3 A
U1= 450 B
r=6 Ом

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Answer 1

U3=I3*R3=9B
R1=U1/I1=450/2=225Om
I2=I3-I1=1A
R2=U2/I2=U3/I2=9Om
1/R=1/R1+1/R2=1/225+1/9=234/2025
R=2025/234
r+R3+R=6+3+2025/234
E=I3*(r+R3+R)=3(9+2025/234)=27+2025/76